Multiple choice

To paint each surface of a square room uniformly, Raja needs 12 litres of paint. If every side of the square room is increased by 50%, then how much extra paint will Raja need?

  1. 15 lt

  2. 12 lt

  3. 6 lt

  4. 9 lt
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A Correct answer
Explanation

Surface area of a room is proportional to the square of the side length. If side increases by 50% (factor 1.5), area increases by (1.5)^2 = 2.25. New paint = 12 * 2.25 = 27. Extra paint = 27 - 12 = 15.

AI explanation

The total surface area of the square room is proportional to the square of its side length. When the side of the room is increased by 50%, the new area becomes (1.5)^2 = 2.25 times the original area, meaning the total paint needed increases by 125%. Since 12 litres covers 100% of the area, the extra 125% requires an additional 15 litres of paint (12 * 1.25).

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